Vertical nanowire semiconductor device and manufacturing method therefor

ABSTRACT

Provided is a method of manufacturing a nanowire semiconductor device, the method including: forming a seed layer on a substrate; forming, on the seed layer, a multilayer in which a first conductive layer, a semiconductor layer, a second conductive layer are sequentially stacked; forming a vertical nanowire above the substrate by patterning the multilayer; crystallizing the vertical nanowire by heat treatment; forming an insulating layer covering the vertical nanowire; forming a gate surrounding a channel area by the semiconductor silicon layer of the vertical nanowire; and forming a metal pad electrically connected to the gate, the first conductive layer, and the second conductive layer.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY

The present application is a continuation of International ApplicationNo. PCT/KR2019/002515, filed on Mar. 5, 2019, which claims priority toand the benefit of the filing dates of Korean Patent Application Nos.10-2018-0034098, filed on Mar. 23, 2018 and 10-2018-0145648, filed onNov. 22, 2018, in the Korean Intellectual Property Office, thedisclosures of which are incorporated herein in their entirety byreference.

TECHNICAL FIELD

The present disclosure relates to an Si nanowire semiconductor deviceand a manufacturing method therefor, and more particularly, to asemiconductor device using a vertical semiconductor nanowire and amanufacturing method therefor.

BACKGROUND

A high-performance semiconductor improves quality of an electronicproduct and comes with cost benefits. A semiconductor device needs tohave high mobility and high reliability, in particular, needs to reducecharacteristic dispersion by having certain characteristics.

AM-OLED displays have been mainly applied as mobile displays of recentsmartphones. As a pixel switching element of such an AM-OLED display, alow temperature polycrystalline silicon thin film transistor (LTPS TFT)having high charge mobility and high reliability is appropriate evenunder high integration.

Excimer laser annealing is mainly used for crystallization of silicon tomanufacture the low temperature polycrystalline silicon thin filmtransistor (LTPS TFT). When such an LTPS TFT is applied to a large areadisplay, crystal grain uniformity of a certain level may not bemaintained, and yield is low.

SUMMARY

Provided is a method of forming a <111>-oriented high-quality Sinanowire by using an MIC technology.

Provided are also a semiconductor device using an Si nanowire and amanufacturing method therefor.

According to an aspect of the present disclosure, a method ofmanufacturing a semiconductor device, includes steps of: (i) forming aseed layer on a substrate, (ii) forming, on the seed layer, a multilayerin which a first conductive layer, a semiconductor layer, a secondconductive layer are sequentially stacked; (iii) forming a verticalnanowire above the substrate by patterning the multilayer; (iv)crystallizing the vertical nanowire by heat treatment; (v) forming aninsulating layer covering the vertical nanowire; (vi) forming a gatesurrounding a channel area by the semiconductor layer of the verticalnanowire; and (vii) forming a metal pad electrically connected to thegate, the first conductive layer, and the second conductive layer.

The method may further include: forming, above the substrate, aninter-layer dielectric (ILD) layer covering the vertical nanowire andhaving a plurality of contact holes corresponding to the firstconductive layer, the second conductive layer, and the gate; andforming, on the ILD layer, a plurality of metal pads respectivelycorresponding to the gate, the first conductive layer, and the secondconductive layer.

The seed layer may be formed of at least one selected from the groupconsisting of NiOx, NiCxOy, NiNxOy, NiCxNyOz, NiCxOy:H, NiNxOy:H,NiCxNyOz:H, NixSiy, and NixGey.

The first conductive layer, the second conductive layer, and thevertical nanowire may include one of Si, SiGe, and Ge.

The first conductive layer and the second conductive layer may besilicon conductive layers, and the semiconductor layer may be a siliconlayer.

The multilayer may include a first multilayer having a p-typesemiconductor layer and an n-type conductive layer, and a secondmultilayer having an n-type semiconductor layer and a p-type conductivelayer.

A first vertical nanowire and a second vertical nanowire may be formedby simultaneously patterning the first multilayer and the secondmultilayer

According to another aspect of the present disclosure, a semiconductordevice, manufactured by the method, includes: (i) a substrate; (ii) afirst conductive layer in a source or drain area formed above thesubstrate; (iii) a semiconductor nanowire of a channel area verticallyupright with respect to the substrate on the first conductive layer;(iv) a second conductive layer of a drain or source area provided on thetop of the semiconductor nanowire; (v) a gate surrounding the channelarea of the vertical nanowire; and (vi) a gate insulating layer locatedbetween the channel area and the gate.

The first conductive layer, the second conductive layer, and thevertical nanowire may include one of Si, SiGe, and Ge.

The first conductive layer and the second conductive layer may besilicon conductive layers, and the semiconductor nanowire may be asingle crystal grain silicon nanowire.

A metal layer may be formed on the second conductive layer, and an NiSi₂contact layer may be provided between the second conductive layer andthe metal layer.

An ILD layer, covering the vertical nanowire and having a plurality ofcontact holes corresponding to the first conductive layer, the secondconductive layer, and the gate, may be formed above the substrate, and aplurality of metal pads respectively corresponding to the gate, thefirst conductive layer, and the second conductive layer may be formed onthe ILD layer.

The vertical nanowire may have a circular or polygonal cross section.

The first conductive layer and the second conductive layer may extendfrom a lower portion of the semiconductor nanowire to a portion directlyunder each contact hole.

Crystals of the semiconductor nanowire and the first and secondconductive layers may be oriented in <111> direction.

According to an example embodiment provides a method of manufacturing asemiconductor nanowire channel in which crystals are grown in <111>orientation and a method of manufacturing a CMOS by applying the same.According to the example embodiment may implement a system on panel(SOP) by manufacturing a high-performance LSI, memory, a sensor, and thelike on a large area substrate According to the example embodimentdescribed above, an ion implantation process for forming a conductivelayer is not separately needed, and an existing activation process isnot also needed. Therefore, according to the example embodiment, ahigh-yield semiconductor device having high mobility, high reliability,and low product-to-product characteristic dispersion may be obtained.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a process for forming a buffer layer and a seed layer on asubstrate during manufacturing a vertical nanowire semiconductor device,according to an example embodiment.

FIG. 2 shows a process for forming a first multilayer for a firsttransistor on the buffer layer during manufacturing a vertical nanowiresemiconductor device, according to an example embodiment.

FIG. 3 shows a process for patterning the multilayer on the substrateduring manufacturing a vertical nanowire semiconductor device, accordingto an example embodiment.

FIG. 4 shows a process for forming a second multilayer for a secondtransistor on the substrate during manufacturing a vertical nanowiresemiconductor device, according to an example embodiment.

FIG. 5 shows a process for forming a first silicon nanowire and a secondsilicon by patterning the first and second multilayer duringmanufacturing a vertical nanowire semiconductor device, according to anexample embodiment.

FIG. 6 shows a process for crystallizing the first and second nanowireby heat treatment during manufacturing a vertical nanowire semiconductordevice, according to an example embodiment.

FIG. 7 shows a process for forming a first insulating layer over thesubstrate during manufacturing a vertical nanowire semiconductor device,according to an example embodiment.

FIG. 8 shows a process for forming a gate insulating layer and a gateare on sides of the first and second silicon nanowires duringmanufacturing a vertical nanowire semiconductor device, according to anexample embodiment.

FIG. 9 shows a process for forming a second insulating layer formedabove the substrate during manufacturing a vertical nanowiresemiconductor device, according to an example embodiment.

FIG. 10 shows a process for removing exposed portions of the gate andthe gate insulating layer during manufacturing a vertical nanowiresemiconductor device, according to an example embodiment.

FIG. 11 shows a process for forming an ILD layer having a plurality ofcontact holes above the substrate during manufacturing a verticalnanowire semiconductor device, according to an example embodiment.

FIG. 12 shows a process for forming metal pads on the ILD layer over thesubstrate during manufacturing a vertical nanowire semiconductor device,according to an example embodiment.

FIG. 13 is a view for explaining a basic structure of a verticalnanowire semiconductor device, according to an example embodiment.

DETAILED DESCRIPTION

Hereinafter, example embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.However, embodiments of the present disclosure may be modified intovarious forms, and the scope of the present disclosure should not beconstrued as being limited by the embodiments described below. Theembodiments of the present disclosure may be interpreted as beingprovided to further completely explain the spirit of the presentdisclosure to one of ordinary skill in the art. Like reference numeralsin the drawings denote like elements. Various elements and areas in thedrawings are schematically drawn. Therefore, the spirit of the presentdisclosure is not limited by the relative size or spacing drawn in theaccompanying drawings. Although the terms first, second etc. may be usedherein to describe various elements, these elements should not belimited by these terms. These terms are only used to distinguish oneelement from another element. For example, a first element may be termeda second element and conversely, the second element may be termed thefirst element without departing from the scope of the presentdisclosure.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “have” when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meanings as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

When a certain embodiment may be implemented differently, a specificprocess order may be performed differently from the described order. Forexample, two processes described in succession may be performedsubstantially simultaneously or may be performed in an order opposite tothe described order.

As such, variations from the shapes of the illustrations as a result,for example, of manufacturing techniques and/or tolerances, are to beexpected. Thus, example embodiments should not be construed as limitedto the particular shapes of regions illustrated herein but may be toinclude deviations in shapes that result, for example, frommanufacturing. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items. The term“substrate” as used herein may mean a substrate itself or a stackstructure including a substrate and a predetermined layer or film formedon the surface thereof. As used herein, “the surface of the substrate”may mean an exposed surface of the substrate itself, or an outer surfaceof a predetermined layer or film formed on the substrate. What isdescribed as “above” or “on” may include not only those directly on incontact but also non-contact above.

Hereinafter, a method of manufacturing a COS device including a verticalnanowire transistor according to an example embodiment will be describedwith reference to the accompanying drawings.

A nanowire transistor according to an example embodiment includes: asubstrate; a first conductive layer in a source or drain area formedabove the substrate; a semiconductor nanowire in a channel areavertically upright on the first conductive layer; a second conductivelayer in a drain or source area provided on the top of the nanowire; agate surrounding the vertical nanowire; and a gate insulating layerlocated between the channel area and the gate.

A method of manufacturing a nanowire transistor according to an exampleembodiment, includes: forming a seed layer on a substrate; forming, onthe seed layer, a multilayer in which a first conductive layer, asemiconductor silicon layer, and a second conductive layer aresequentially stacked; forming a nanowire above the substrate bypatterning the multilayer; crystallizing the nanowire by heat treatment;forming an insulating layer covering the first conductive layer; forminga gate surrounding a channel area by a semiconductor layer of thenanowire; and forming a metal pad electrically connected to the secondconductive layer.

Hereinafter, a method of manufacturing a CMOS according to an exampleembodiment as described above will be described. Through understandingof the following technical content, a structure of a vertical siliconnanowire transistor and a method of manufacturing the same may be easilyderived. In the following embodiments, a method of manufacturing a CMOSdevice by using amorphous silicon as a semiconductor material will bedescribed as an example.

A shown in FIG. 1, a buffer layer 101 and a seed layer 102 aresequentially formed on a substrate 100.

The buffer layer 101 may be provided by a top-most dielectric layer of astack structure already formed through a preceding process. The bufferlayer 101 may be formed of, for example, an insulating material such asSiO₂, SiNx, SiONx, or AlOx.

The seed layer 102 on the buffer layer 101 may include, as Ni-basedoxide, at least one selected from the group consisting of NiOx, NiCxOy,NiNxOy, NiCxNyOz, NiCxOy:H, NiNxOy:H, NiCxNyOz:H, NixSiy, and NixGey.

As shown in FIG. 2, a multilayer ML, including a first siliconconductive layer 102, a silicon semiconductor layer 104, a secondsilicon conductive layer 105, and a metal layer 106 on the secondsilicon conductive layer 105 that are in an amorphous state, is formedon the seed layer 102. For example, the multilayer ML may have a stackstructure of n+ a-Si/p a-Si/n+a-Si/TiN for obtaining a PMOS transistorhaving a p-type silicon channel and n-type silicon conductive layers onand underneath the p-type silicon channel.

As shown in FIG. 3, the multilayer ML is patterned by applying aphotoresist (PR) mask to an area of a first transistor, for example, anarea of a first transistor TR1 defined as a PMOS transistor area abovethe substrate. The patterning of the multilayer ML may be performed byan existing photography method. Due to the patterning of the multilayerML, a first multilayer ML1 remains merely in the area of the firsttransistor TR1, and the seed layer 102 on the substrate 100 is exposedin a remaining portion.

As shown in FIG. 4, a second multilayer ML2 for forming a secondtransistor, for example, an NMOS transistor in a portion defined as anarea of a second transistor TR2 is formed above the substrate 100. Thesecond multilayer ML2 may have a stack structure of p+ a-Si/n a-Si/p+a-Si/TiN. The second multilayer ML2 may be obtained through a processsimilar to a process of forming the first multilayer ML1 and may have astructure in which a first silicon conductive layer 107, a siliconsemiconductor layer 108, a second silicon conductive layer 109, and ametal layer 110 are stacked from the bottom.

As shown in FIG. 5, the first multilayer ML1 and the second multilayerML2 are simultaneously patterned to form a first silicon nanowire W1 anda second silicon nanowire W2 for vertical first transistor and secondtransistor on the first and second silicon conductive layers 103 and 107Here, the patterning is performed down to both of the siliconsemiconductor layers 104 and 108 in the areas of the first and secondtransistors TR1 and TR2, and both of the first silicon conductive layers103 and 107 underneath the same are excluded from patterning. Therefore,the first silicon conductive layers 103 and 107 extend to the outside ofthe first and second silicon nanowires W1 and W2 and extend directlyunder a corresponding contact hole of an ILD layer to be describedlater.

The first and second silicon nanowires W1 and W2 may have cylindricalshapes and, according to another embodiment, may have rectangular pillarshapes or polygonal pillar shapes. A particular structure or shape ofsuch a silicon nanowire does not limit the technical scope of variousexample embodiments.

As shown in FIG. 6, the first and second silicon nanowires W1 and W2 arecrystallized by performing metal induced crystallization (MIC) throughlow temperature heat treatment. In this crystallization process, Ni of aseed layer reacts with Si to produce NiSi₂, and NiSi₂ reaches the firstand second silicon conductive layers 105 and 109 that are the topmostportions of the first and second silicon nanowires W1 and W2 to form anNiSi₂ contact layers 102′, 102′ between the second silicon conductivelayers 105, 109 and the metal layers 106, 110.

A crystallized nanowire has crystal orientation in (111) direction.After such heat treatment, NiSi₂ that may remain on the outercircumferential surface of a single crystal grain silicon nanowire maybe removed by wet cleaning using HNO₃, HF, or the like.

As shown in FIG. 7, a first insulating layer 111 is formed to a presetthickness on the first silicon conductive layers 103 and 107 above thesubstrate 100. The first insulating layer 111 may be manufactured by amethod of forming and etching back an organic insulator such aspolyimide (PI) or a high-density plasma (HDP) oxide layer. Here, thefirst insulating layer 111 covers merely lower portions of the first andsecond silicon nanowires W1 and W2, and a thickness thereof is setaccording to a location of a lower boundary of a gate to be formed in asubsequent process.

As shown in FIG. 8, a gate insulating layer 112 and a gate 113 areformed on sides of the first and second silicon nanowires W1 and W2.This process involves deposition and patterning processes of aninsulating material and a gate material. Here, the gate insulating layer112 may be formed of SiO₂, and the gate 113 may be formed of MoW. Inthis case, the gate insulating layer 112 and the gate 113 are in anincomplete state and also cover upper portions of the first and secondsilicon nanowires W1 and W2 as well. Also, a pad 113 a as a terminal forexternal connection of the gate 113 is provided underneath the gate 113and extends a preset length in a direction parallel with the plane ofthe substrate 100.

As shown in FIG. 9, a second insulating layer 114 is formed as aplanarization layer to a preset thickness above the substrate 100. Thetop surface of the second insulating layer 114 is located under thecontact layers 102′ of the first and second silicon nanowires W1 and W2.The second insulating layer 114 is used as a mask for removing unneededportions of the gate insulating layer 112 and the gate 113 remaining atthe upper portions of the first and second silicon nanowires W1 and W2.The second insulating layer 114 having the adjusted height or thicknessas described above may be manufactured by forming and etching back anorganic insulator such as polyimide (PI) or an HDP oxide layer.

As shown in FIG. 10, exposed portions of the gate 113 and the gateinsulating layer 112 that are not covered with the second insulatinglayer 114 are removed by isotropic etch, thereby completely exposingboth of the second silicon conductive layers 105 and 109, and both ofthe contact layers 102′, 102′ underneath the same, which are the upperportions of the first and second nanowires W1 and W2. In this process,the gate 113 that is incomplete is completed.

As shown in FIG. 11, ILD layer 115 having a plurality of contact holes115 a, 115 b, 115 c, 116 a, 116 b, and 116 c is formed above thesubstrate 100. The ILD layer 115 covers a CMOS semiconductor deviceincluding the first transistor TR1 by the first silicon nanowire W1 andthe silicon nanowire transistor by the second silicon nanowire W2.

As shown in FIG. 12, metal pads 117 a, 117 b, 117 c, 118 a, 118 b, and118 c are formed on the ILD layer 115 to be electrically connected tothe second silicon conductive layers 105 and 109 and the gate 113 of thefirst and second transistors TR1 and TR2 thereunder through the contactholes 115 a, 115 b, 115 c, 116 a, 116 b, and 116 c.

Following this process, an additional process may be performed accordingto the design of an electronic device to be applied.

As schematically shown in FIG. 13, a nanowire semiconductor devicedescried above through the above embodiment includes a single crystalgrain silicon nanowire, which is a vertical channel between a source anda drain arranged in parallel above a substrate, and a gate surroundingthe single crystal grain silicon nanowire. Here, the single crystalgrain silicon nanowire has a crystal structure that is grown in (111)direction.

When the crystal growth of the single crystal grain silicon nanowire isachieved by MIC, and an amorphous layer formed of NiOx, NiCxOy, NiNxOy,NiCxNyOz, NiCxOy:H, NiNxOy:H, NiCxNyOz:H, NixSiy, NixGey, or the likemay be applied as a crystallization catalyst layer. Such a catalystlayer may be deposited according to an ALD method. In the description ofthe above embodiment, a silicon semiconductor layer corresponding to achannel may be doped with n-type or p-type dopant and, according toanother embodiment, may be formed of intrinsic silicon.

MIC heat treatment for crystallizing amorphous silicon may be performedin a normal heating furnace or may be performed in a heating furnace towhich an electromagnetic field is applied. In the case of a verticalsilicon nanowire providing a channel, NiSi₂ inducing crystallizationrises to the topmost surface of a second silicon conductive layer, risesto the surface, and contacts a metal layer to function as a contactlayer. A silicon nanowire described in an example embodiment may beapplied not only to manufacture a transistor but also to manufacture amemory device, and a diode.

In the description of the above embodiment, one transistor includes onenanowire. However, according to another embodiment, one transistor mayinclude a plurality of nanowires and thus have a multichannel structure.

Also, in a semiconductor device as described above, a first conductivelayer and a second conductive layer may have different doping types, andthus, a tunneling field effect transistor having a structure of p+-i-n+or n+-i-p+ may be manufactured.

In the above-described embodiment, silicon is applied as a semiconductormaterial, but SiGe, Ge, or the like may be applied as the semiconductormaterial in addition to silicon.

According to another embodiment of the present disclosure, on the basisof a method as described above, a silicon solar cell may be manufacturedabove a polycrystalline silicon substrate or a heterogeneous substrate,a 3D stack memory may be manufactured by manufacturing a 3D stackstructure, and various types of devices may be integrated above onesubstrate.

A method of manufacturing a semiconductor device according to anembodiment of the present disclosure has been described to aid inunderstanding the present disclosure with reference to the embodimentsshown in the drawings, but this is merely an example. It will beunderstood by one of ordinary skill in the art that variousmodifications and other equivalent embodiments are possible therefrom.Therefore, the technical scope of the present disclosure should bedefined by the appended claims.

What is claimed is:
 1. A method of manufacturing a nanowiresemiconductor device, the method comprising: forming a seed layer on asubstrate; forming, on the seed layer, a multilayer in which a firstconductive layer, a semiconductor layer, a second conductive layer aresequentially stacked; forming a vertical nanowire above the substrate bypatterning the multilayer; crystallizing the vertical nanowire by heattreatment; forming an insulating layer covering the vertical nanowire;forming a gate surrounding a channel area by the semiconductor layer ofthe vertical nanowire; and forming a metal pad electrically connected tothe gate, the first conductive layer, and the second conductive layer.2. The method of claim 1, further comprising: forming, above thesubstrate, an ILD layer covering the vertical nanowire and having aplurality of contact holes corresponding to the first conductive layer,the second conductive layer, and the gate; and forming, on the ILDlayer, a plurality of metal pads respectively corresponding to the gate,the first conductive layer, and the second conductive layer.
 3. Themethod of claim 1, wherein the seed layer is formed of at least oneselected from the group consisting of NiOx, NiCxOy, NiNxOy, NiCxNyOz,NiCxOy:H, NiNxOy:H, NiCxNyOz:H, NixSiy, and NixGey.
 4. The method ofclaim 2, wherein the seed layer is formed of at least one selected fromthe group consisting of NiOx, NiCxOy, NiNxOy, NiCxNyOz, NiCxOy:H,NiNxOy:H, NiCxNyOz:H, NixSiy, and NixGey.
 5. The method of claim 1,wherein the first conductive layer, the second conductive layer, and thevertical nanowire include one of Si, SiGe, and Ge.
 6. The method ofclaim 2, wherein the first conductive layer, the second layer, and thevertical nanowire include one of Si, SiGe, and Ge.
 7. The method ofclaim 5, wherein the multilayer includes a first multilayer having ap-type channel and an n-type conductive layer, and a second multilayerhaving an n-type channel and a p-type conductive layer.
 8. The method ofclaim 7, wherein a first nanowire for a PMOS semiconductor device and asecond nanowire for an NMOS semiconductor device are formed bysimultaneously patterning the first multilayer and the secondmultilayer.
 9. The method of claim 1, wherein the multilayer includes afirst multilayer having a p-type channel and an n-type conductive layer,and a second multilayer having an n-type channel and a p-type conductivelayer.
 10. A vertical nanowire semiconductor device manufactured by themethod of claim 1, the vertical nanowire semiconductor devicecomprising: a substrate; a first conductive layer in a source or drainarea formed above the substrate; a semiconductor nanowire of a channelarea vertically upright with respect to the substrate on the firstconductive layer; a second conductive layer of a drain or source areaprovided on the top of the semiconductor nanowire; a gate surroundingthe channel area of the vertical nanowire; and a gate insulating layerlocated between the channel area and the gate.
 11. The vertical nanowiresemiconductor device of claim 10, wherein the seed layer is formed of atleast one selected from the group consisting of NiOx, NiCxOy, NiNxOy,NiCxNyOz, NiCxOy:H, NiNxOy:H, NiCxNyOz:H, NixSiy, and NixGey.
 12. Thevertical nanowire semiconductor device of claim 10, wherein the firstconductive layer, the second conductive layer, and the semiconductornanowire include one of Si, SiGe, and Ge.
 13. The vertical nanowiresemiconductor device of claim 11, wherein the first conductive layer,the second conductive layer, and the semiconductor nanowire include oneof Si, SiGe, and Ge.
 14. The vertical nanowire semiconductor device ofclaim 10, wherein the semiconductor nanowire includes a first nanowirefor a PMOS semiconductor device and a second nanowire for an NMOSsemiconductor device.
 15. The vertical nanowire semiconductor device ofclaim 11, wherein each of the PMOS semiconductor device and the NMOSsemiconductor device has a multichannel structure having a plurality ofnanowires.
 16. A vertical nanowire semiconductor device manufactured bythe method of claim 2, the vertical nanowire semiconductor devicecomprising: a substrate; a first conductive layer in a source or drainarea formed above the substrate; a semiconductor nanowire of a channelarea vertically upright with respect to the substrate on the firstconductive layer; a second conductive layer of a drain or source areaprovided on the top of the semiconductor nanowire; a gate surroundingthe channel area of the vertical nanowire; and a gate insulating layerlocated between the channel area and the gate.